Neural basis of learning and preference during social decision-making

Social decision-making is arguably the most complex cognitive function performed by the human brain. This is due to two unique features of social decision-making. First, predicting the behaviors of others is extremely difficult. Second, humans often take into consideration the well-beings of others during decision-making, but this is influenced by many contextual factors. Despite such complexity, studies on the neural basis of social decision-making have made substantial progress in the last several years. They demonstrated that the core brain areas involved in reinforcement learning and valuation, such as the ventral striatum and orbitofrontal cortex, make important contribution to social decision-making. Furthermore, the contribution of brain systems implicated for theory of mind during decision-making is being elucidated. Future studies are expected to provide additional details about the nature of information channeled through these brain areas.

An imaging genetics approach to understanding social influence

Normative social influences shape nearly every aspect of our lives, yet the biological processes mediating the impact of these social influences on behavior remain incompletely understood. In this Hypothesis, we outline a theoretical framework and an integrative research approach to the study of social influences on the brain and genetic moderators of such effects. First, we review neuroimaging evidence linking social influence and conformity to the brain's reward system. We next review neuroimaging evidence linking social punishment (exclusion) to brain systems involved in the experience of pain, as well as evidence linking exclusion to conformity. We suggest that genetic variants that increase sensitivity to social cues may predispose individuals to be more sensitive to either social rewards or punishments (or potentially both), which in turn increases conformity and susceptibility to normative social influences more broadly. To this end, we review evidence for genetic moderators of neurochemical responses in the brain, and suggest ways in which genes and pharmacology may modulate sensitivity to social influences. We conclude by proposing an integrative imaging genetics approach to the study of brain mediators and genetic modulators of a variety of social influences on human attitudes, beliefs, and actions.

The role of prediction in social neuroscience

Research has shown that the brain is constantly making predictions about future events. Theories of prediction in perception, action and learning suggest that the brain serves to reduce the discrepancies between expectation and actual experience, i.e., by reducing the prediction error. Forward models of action and perception propose the generation of a predictive internal representation of the expected sensory outcome, which is matched to the actual sensory feedback. Shared neural representations have been found when experiencing one's own and observing other's actions, rewards, errors, and emotions such as fear and pain. These general principles of the “predictive brain” are well established and have already begun to be applied to social aspects of cognition. The application and relevance of these predictive principles to social cognition are discussed in this article. Evidence is presented to argue that simple non-social cognitive processes can be extended to explain complex cognitive processes required for social interaction, with common neural activity seen for both social and non-social cognitions. A number of studies are included which demonstrate that bottom-up sensory input and top-down expectancies can be modulated by social information. The concept of competing social forward models and a partially distinct category of social prediction errors are introduced. The evolutionary implications of a “social predictive brain” are also mentioned, along with the implications on psychopathology. The review presents a number of testable hypotheses and novel comparisons that aim to stimulate further discussion and integration between currently disparate fields of research, with regard to computational models, behavioral and neurophysiological data. This promotes a relatively new platform for inquiry in social neuroscience with implications in social learning, theory of mind, empathy, the evolution of the social brain, and potential strategies for treating social cognitive deficits.

Positive interaction of social comparison and personal responsibility for outcomes

We formulate and test a model that allows sharp separation between two different ways in which environment affects evaluation of outcomes, by comparing social vs. private and personal responsibility vs. chance. In the experiment, subjects chose between two lotteries, one low-risk and one high-risk. They could then observe the outcomes. By varying the environment between private (they could observe the outcome of the chosen lottery and the outcome of the lottery they had not chosen) and social (they could observe the outcome of the lottery chosen by another subject) we can differentiate the response and brain activity following the feedback in social and private settings. The evidence suggests that envy and pride are significant motives driving decisions and outcomes evaluation, stronger than private emotions like regret and rejoice, with ventral striatum playing a key role. When we focus on the outcome evaluation stage we demonstrate that BOLD signal in ventral striatum is increasing in the difference between obtained and counterfactual payoffs. For a given difference in payoffs, striatal responses are more pronounced in social than in private environment. Moreover, a positive interaction (complementarity) between social comparison and personal responsibility is reflected in the pattern of activity in the ventral striatum. At decision stage we observe getting ahead of the Joneses effect in ventral striatum with subjective value of risk larger in social than in private environment.

Inferring mental states from neuroimaging data: from reverse inference to large-scale decoding

A common goal of neuroimaging research is to use imaging data to identify the mental processes that are engaged when a subject performs a mental task. The use of reasoning from activation to mental functions, known as "reverse inference," has been previously criticized on the basis that it does not take into account how selectively the area is activated by the mental process in question. In this Perspective, I outline the critique of informal reverse inference and describe a number of new developments that provide the ability to more formally test the predictive power of neuroimaging data.

Causes of social reward differences encoded in human brain

Rewards may be due to skill, effort, and luck, and the social perception of inequality in rewards among individuals may depend on what produced the inequality. Rewards due to skill produce a conflict: higher outcomes of others in this case are considered deserved, and this counters incentives to reduce inequality. However, they also signal superior skill and for this reason induce strong negative affect in those who perform less, which increases the incentive to reduce the inequality. The neurobiological mechanisms underlying evaluation of rewards due to skill, effort, and luck are still unknown. We scanned brain activity of subjects as they perceived monetary rewards caused by skill, effort, or luck. Subjects could subtract from others. Subtraction was larger, everything else being equal, in luck but increased more as the difference in outcomes grew in skill. Similarly, reward-related activation in medial orbitofrontal cortex was more sensitive to the difference in relative outcomes in skill trials. Orbitofrontal activation reflecting comparative reward advantage predicted by how much subjects reduced unfavorable reward inequality later on in the trial. Thus medial orbitofrontal cortex activity reflects the causes of reward and predicts actions that reduce inequality.

Social Comparison Affects Brain Responses to Fairness in Asset Division: An ERP Study with the Ultimatum Game

Previous studies have shown that social comparison influences individual’s fairness consideration and other-regarding behavior. However, it is not clear how social comparison affects the brain activity in evaluating fairness during asset distribution. In this study, participants, acting as recipients in the ultimatum game, were informed not only of offers to themselves but also of the average amount of offers in other allocator–recipient dyads. Behavioral results showed that the participants were more likely to reject division schemes when they were offered less than the other recipients, especially when the offers were highly unequal. Event-related brain potentials recorded from the participants showed that highly unequal offers elicited more negative-going medial frontal negativity than moderately unequal offers in an early time window (270–360 ms) and this effect was not significantly modulated by social comparison. In a later time window (450–650 ms), however, the late positive potential (LPP) was more positive for moderately unequal offers than for highly unequal offers when the other recipients were offered less than the participants, whereas this distinction disappeared when the other recipients were offered the same as or more than the participants. These findings suggest that the brain activity in evaluating fairness in asset division entails both an earlier (semi-) automatic process in which the brain responds to fairness at an abstract level and a later appraisal process in which factors related to social comparison and fairness norms come into play.

Effects of outcomes and random arbitration on emotions in a competitive gambling task

Research on self-serving biases in judgments and decision-making suggests that individuals first evaluate the outcomes they get, and then the procedures by which these outcomes were obtained. Evidence also suggests that the appraisal of the former (outcome favorability) can bias the appraisal of the latter (procedural fairness). We investigated the nature of the emotions that are elicited by these appraisals by using a new paradigm in which participants performed a choice task between pairs of competing gambles against a virtual opponent. Conflicts (when the participant selected the same gamble as his virtual opponent) were resolved by a neutral arbitrator who either confirmed the participant’s choice (“pro-self”) or attributed his gamble to the virtual opponent (“pro-competitor”). Trials in which the participant and his virtual opponent selected different gambles (“no-conflict”) served as a control condition. In order to validate this new task, emotional reactions to the outcomes of the gambles were measured using self-reports, skin conductance responses, and facial electromyography (zygomaticus, corrugator, and frontalis). In no-conflict trials, effects of counterfactual thinking and social comparison resulted in (i) increased happiness as well as SCR and zygomaticus activity for wins compared to losses (valence effect) and for high compared to low gains (magnitude effect), and (ii) increased anger, regret, disappointment, and envy for losses compared to wins (valence effect). More importantly, compared to no-conflict trials and to pro-self awards with similar outcomes, pro-competitor awards increased subjective reports of anger for unfavorable outcomes, and increased happiness and guilt for favorable outcomes. Although the outcomes were independent from the arbitrators’ decisions, and both the arbitrators’ decisions and the outcomes were kept equally likely, individuals tended to attribute their outcomes to unfair arbitrators, reacting emotionally, especially when the modification of their initial choice for a gamble led to a negative outcome.

Medial prefrontal cortex and striatum mediate the influence of social comparison on the decision process

We compared private and social decision making to investigate the neural underpinnings of the effect of social comparison on risky choices. We measured brain activity using functional MRI while participants chose between two lotteries: in the private condition, they observed the outcome of the unchosen lottery, and in the social condition, the outcome of the lottery chosen by another person. The striatum, a reward-related brain structure, showed higher activity when participants won more than their counterpart (social gains) compared with winning in isolation and lower activity when they won less than their counterpart (social loss) compared with private loss. The medial prefrontal cortex, implicated in social reasoning, was more activated by social gains than all other events. Sensitivity to social gains influenced both brain activity and behavior during subsequent choices. Specifically, striatal activity associated with social gains predicted medial prefrontal cortex activity during social choices, and experienced social gains induced more risky and competitive behavior in later trials. These results show that interplay between reward and social reasoning networks mediates the influence of social comparison on the decision process.

Antiferromagnetic character of workplace stress

We study the nature of workplace stress from the aspect of human-human interactions. We investigated the distribution of Center for Epidemiological Studies Depression Scale scores, a measure of the degree of stress, in workplaces. We found that the degree of stress people experience when around other highly stressed people tends to be low, and vice versa. A simulation based on a model describing microlevel human-human interaction reproduced this observed phenomena and revealed that the energy state of a face-to-face communication network correlates with workplace stress macroscopically.

Bounded empathy: neural responses to outgroup targets' (mis)fortunes

The current study investigates whether mere stereotypes are sufficient to modulate empathic responses to other people's (mis)fortunes, how these modulations manifest in the brain, and whether affective and neural responses relate to endorsing harm against different outgroup targets. Participants feel least bad when misfortunes befall envied targets and worst when misfortunes befall pitied targets, as compared with ingroup targets. Participants are also least willing to endorse harming pitied targets, despite pitied targets being outgroup members. However, those participants who exhibit increased activation in functionally defined insula/middle frontal gyrus when viewing pity targets experience positive events not only report feeling worse about those events but also more willing to harm pity targets in a tradeoff scenario. Similarly, increased activation in anatomically defined bilateral anterior insula, in response to positive events, predicts increased willingness to harm envy targets, but decreased willingness to harm ingroup targets, above and beyond self-reported affect in response to the events. Stereotypes' specific content and not just outgroup membership modulates empathic responses and related behavioral consequences including harm.

Stereotypes and Schadenfreude: Affective and physiological markers of pleasure at outgroup misfortunes

People often fail to empathize with outgroup members, and sometimes even experience Schadenfreude-pleasure-in response to their misfortunes. One potent predictor of Schadenfreude is envy. According to the Stereotype Content Model, envy is elicited by groups whose stereotypes comprise status and competitiveness. These are the first studies to investigate whether stereotypes are sufficient to elicit pleasure in response to high-status, competitive targets' misfortunes. Study 1 participants feel least negative when misfortunes befall high-status, competitive targets as compared to other social targets; participants' facial muscles simultaneously exhibit a pattern consistent with positive affect (i.e., smiling). Study 2 attenuates the Schadenfreude response by manipulating status and competition-relevant information; Schadenfreude decreases when the target-group member has lowered status or is cooperative. Stereotypes' specific content, and not just individual relationships with targets themselves, can predict Schadenfreude.

The neuroscience of social decision-making

Given that we live in highly complex social environments, many of our most important decisions are made in the context of social interactions. Simple but sophisticated tasks from a branch of experimental economics known as game theory have been used to study social decision-making in the laboratory setting, and a variety of neuroscience methods have been used to probe the underlying neural systems. This approach is informing our knowledge of the neural mechanisms that support decisions about trust, reciprocity, altruism, fairness, revenge, social punishment, social norm conformity, social learning, and competition. Neural systems involved in reward and reinforcement, pain and punishment, mentalizing, delaying gratification, and emotion regulation are commonly recruited for social decisions. This review also highlights the role of the prefrontal cortex in prudent social decision-making, at least when social environments are relatively stable. In addition, recent progress has been made in understanding the neural bases of individual variation in social decision-making.

Vicarious reinforcement in rhesus macaques (macaca mulatta)

What happens to others profoundly influences our own behavior. Such other-regarding outcomes can drive observational learning, as well as motivate cooperation, charity, empathy, and even spite. Vicarious reinforcement may serve as one of the critical mechanisms mediating the influence of other-regarding outcomes on behavior and decision-making in groups. Here we show that rhesus macaques spontaneously derive vicarious reinforcement from observing rewards given to another monkey, and that this reinforcement can motivate them to subsequently deliver or withhold rewards from the other animal. We exploited Pavlovian and instrumental conditioning to associate rewards to self (M1) and/or rewards to another monkey (M2) with visual cues. M1s made more errors in the instrumental trials when cues predicted reward to M2 compared to when cues predicted reward to M1, but made even more errors when cues predicted reward to no one. In subsequent preference tests between pairs of conditioned cues, M1s preferred cues paired with reward to M2 over cues paired with reward to no one. By contrast, M1s preferred cues paired with reward to self over cues paired with reward to both monkeys simultaneously. Rates of attention to M2 strongly predicted the strength and valence of vicarious reinforcement. These patterns of behavior, which were absent in non-social control trials, are consistent with vicarious reinforcement based upon sensitivity to observed, or counterfactual, outcomes with respect to another individual. Vicarious reward may play a critical role in shaping cooperation and competition, as well as motivating observational learning and group coordination in rhesus macaques, much as it does in humans. We propose that vicarious reinforcement signals mediate these behaviors via homologous neural circuits involved in reinforcement learning and decision-making.

Hypothetical and real choice differentially activate common valuation areas

Hypothetical reports of intended behavior are commonly used to draw conclusions about real choices. A fundamental question in decision neuroscience is whether the same type of valuation and choice computations are performed in hypothetical and real decisions. We investigated this question using functional magnetic resonance imaging while human subjects made real and hypothetical choices about purchases of consumer goods. We found that activity in common areas of the orbitofrontal cortex and the ventral striatum correlated with behavioral measures of the stimulus value of the goods in both types of decision. Furthermore, we found that activity in these regions was stronger in response to the stimulus value signals in the real choice condition. The findings suggest that the difference between real and hypothetical choice is primarily attributable to variations in the value computations of the medial orbitofrontal cortex and the ventral striatum, and not attributable to the use of different valuation systems, or to the computation of stronger stimulus value signals in the hypothetical condition.

The envious brain: the neural basis of social comparison

Humans have a drive to evaluate themselves by examining their abilities and outcomes in comparison to others. The present study examined the emotional and neural correlates of upward social comparison (comparison with those who have more) and downward social comparison (comparison with those who have less). Two experiments were conducted with volunteers in an interactive game of chance, in which a putative player won or lost more money than the participant. The results showed that even when participants lost money, they expressed joy and schadenfreude (gloating) if the other player had lost more money. On the other hand when they actually won money, but the other player had won more they expressed envy. This pattern was also demonstrated in a differential BOLD response in the ventral striatum. Comparing the activations between an actual gain and a relative gain indicated that even when a person loses money, merely adding information about another person's greater loss may increase ventral striatum activations to a point where these activations are similar to those of an actual gain. We suggest that the ventral striatum plays a role in mediating the emotional consequences of social comparison.

Us versus them: social identity shapes neural responses to intergroup competition and harm

Intergroup competition makes social identity salient, which in turn affects how people respond to competitors' hardships. The failures of an in-group member are painful, whereas those of a rival out-group member may give pleasure-a feeling that may motivate harming rivals. The present study examined whether valuation-related neural responses to rival groups' failures correlate with likelihood of harming individuals associated with those rivals. Avid fans of the Red Sox and Yankees teams viewed baseball plays while undergoing functional magnetic resonance imaging. Subjectively negative outcomes (failure of the favored team or success of the rival team) activated anterior cingulate cortex and insula, whereas positive outcomes (success of the favored team or failure of the rival team, even against a third team) activated ventral striatum. The ventral striatum effect, associated with subjective pleasure, also correlated with self-reported likelihood of aggressing against a fan of the rival team (controlling for general aggression). Outcomes of social group competition can directly affect primary reward-processing neural systems, which has implications for intergroup harm.

Depression: a repair response to stress-induced neuronal microdamage that can grade into a chronic neuroinflammatory condition?

Depression is a major contributor to the global burden of disease and disability, yet it is poorly understood. Here we review data supporting a novel theoretical model for the biology of depression. In this model, a stressful life event leads to microdamage in the brain. This damage triggers an injury repair response consisting of a neuroinflammatory phase to clear cellular debris and a spontaneous tissue regeneration phase involving neurotrophins and neurogenesis. During healing, released inflammatory mediators trigger sickness behavior and psychological pain via mechanisms similar to those that produce physical pain during wound healing. The depression remits if the neuronal injury repair process resolves successfully. Importantly, however, the acute psychological pain and neuroinflammation often transition to chronicity and develop into pathological depressive states. This hypothesis for depression explains substantially more data than alternative models, including why emerging data show that analgesic, anti-inflammatory, pro-neurogenic and pro-neurotrophic treatments have antidepressant effects. Thus, an acute depressive episode can be conceptualized as a normally self-limiting but highly error-prone process of recuperation from stress-triggered neuronal microdamage.

The missing p in psychiatric training: why it is important to teach pain to psychiatrists

CONTEXT

Pain problems are exceedingly prevalent among psychiatric patients. Moreover, clinical impressions and neurobiological research suggest that physical and psychological aspects of pain are closely related entities. Nonetheless, remarkably few pain-related themes are currently included in psychiatric residency training.

OBJECTIVES

To provide clinical and scientific rationale for psychiatric-training enrichment with basic tenets of pain medicine and to raise the awareness and sensitivity of physicians, scientists, and educators to this important yet unmet clinical and public health need.

RESULTS

We present 3 lines of translational research evidence, extracted from a comprehensive literature review, in support of our objectives. First, the neuroanatomical and functional overlap between pain and emotion/reward/motivation brain circuitry suggests integration and mutual modulation of these systems. Second, psychiatric disorders are commonly associated with alterations in pain processing, whereas chronic pain may impair emotional and neurocognitive functioning. Third, given its stressful nature, pain may serve as a functional probe for unraveling pathophysiological mechanisms inherent in psychiatric morbidity.

CONCLUSIONS

Pain training in psychiatry will contribute to deeper and more sophisticated insight into both pain syndromes and general psychiatric morbidity regardless of patients' pain status. Furthermore, it will ease the artificial boundaries separating psychiatric and medical formulations of brain disorders, thus fostering cross-fertilizing interactions among specialists in various disciplines entrusted with the care of patients experiencing pain.

Failing where others have succeeded: Medial Frontal Negativity tracks failure in a social context

Most of us can appreciate that it feels worse to fail when people around you are successful than when others are also failing. Indeed, comparison with other individuals is of central importance within social groups. Despite the importance of relative success or failure for human decision making and even well-being, the underlying neurobiological substrate of this social comparison process is not well understood. In the present study, ERPs were recorded while two participants received feedback on both their own, and the other participant's performance on each trial. The results showed that medial frontal negativity, an ERP component associated with deviations from the desired outcome, is particularly enhanced when an individual's own outcomes are worse than those of others. These results indicate that the way the brain evaluates the success of our actions is crucially dependent on the success or failure of others.

Learning from other people's experience: a neuroimaging study of decisional interactive-learning

Decision-making is strongly influenced by the counterfactual anticipation of personal regret and relief, through a learning process involving the ventromedial-prefrontal cortex. We previously reported that observing the regretful outcomes of another's choices reactivates the regret-network. Here we extend those findings by investigating whether this resonant mechanism also underpins interactive-learning from others' previous outcomes. In this functional-Magnetic-Resonance-Imaging study 24 subjects either played a gambling task or observed another player's risky/non-risky choices and resulting outcomes, thus experiencing personal or shared regret/relief for risky/non-risky decisions. Subjects' risk-aptitude in subsequent choices was significantly influenced by both their and the other's previous outcomes. This influence reflected in cerebral regions specifically coding the effect of previously experienced regret/relief, as indexed by the difference between factual and counterfactual outcomes in the last trial, when making a new choice. The subgenual cortex and caudate nucleus tracked the outcomes that increased risk-seeking (relief for a risky choice, and regret for a non-risky choice), while activity in the ventromedial-prefrontal cortex, amygdala and periaqueductal gray-matter reflected those reducing risk-seeking (relief for a non-risky choice, and regret for a risky choice). Crucially, a subset of the involved regions was also activated when subjects chose after observing the other player's outcomes, leading to the same behavioural change as in a first person experience. This resonant neural mechanism at choice may subserve interactive-learning in decision-making.

Cortico-basal ganglia circuitry: a review of key research and implications for functional connectivity studies of mood and anxiety disorders

There is considerable evidence that dysfunction of the cortico-basal ganglia circuits may be associated with several mood and anxiety disorders. However, it is unclear whether circuit abnormalities contribute directly either to the neurobiology of these conditions or to the manifestation of symptoms. Understanding the role of these pathways in psychiatric illness has been limited by an incomplete characterization of normal function. In recent years, studies using animal models and human functional imaging have greatly expanded the literature describing normal cortico-basal ganglia circuit function. In this paper, recent key studies of circuit function using human and animal models are reviewed and integrated with findings from other studies conducted over the previous decades. The literature suggests several hypotheses of cortico-basal ganglia circuitry function in mood and anxiety disorders that warrant further exploration. Hypotheses are proposed herein based upon the cortico-basal ganglia mechanisms of: (1) feedforward and feedback control, (2) circuit integration and (3) emotional control. These are presented as models of circuit function, which may be particularly relevant to future investigations using neuroimaging and functional connectivity analyses.

Reduced gray matter volume of dorsal cingulate cortex in patients with obsessive-compulsive disorder: a voxel-based morphometric study

AIMS

Previous morphometric studies using magnetic resonance imaging (MRI) have revealed structural brain abnormalities in obsessive-compulsive disorder (OCD). The aim of the present study was to investigate the alterations in brain structure of patients with OCD using a voxel-based morphometry (VBM) method.

METHODS

Sixteen patients with OCD free of comorbid major depression, and 32 sex- and age-matched healthy subjects underwent MRI using a 1.5-T MR scanner. OCD severity was assessed with the Yale-Brown Obsessive-Compulsive Scale (mean ± SD: 22 ± 7.6; range: 7-32). MR images were spatially normalized and segmented using the VBM5 package (http://dbm.neuro.uni-jena.de/vbm/). Statistical analysis was performed using statistical parametric mapping software.

RESULTS

Significant reductions in regional gray matter volume were detected in the left caudal anterior cingulate cortex and right dorsal posterior cingulate cortex in the patients with OCD as compared to healthy controls (uncorrected, P < 0.001). No significant differences in white matter volumes were observed in any brain regions of the patients. No significant correlation between Yale-Brown Obsessive-Compulsive Scale score and regional gray matter or white matter volume was observed.

CONCLUSIONS

Regional gray matter alteration in the dorsal cingulate cortex, which is suggested to play a role in non-emotional cognitive processes, may be related to the pathophysiology in OCD.

When giving is good: ventromedial prefrontal cortex activation for others' intentions

In social decision-making, people care both about others' outcomes and their intentions to help or harm. How the brain integrates representations of others' intentions with their outcomes, however, is unknown. In this study, participants inferred others' decisions in an economic game during functional magnetic resonance imaging. When the game was described in terms of donations, ventromedial prefrontal cortex (VMPFC) activation increased for inferring generous play and decreased for inferring selfish play. When the game was described in terms of individual savings, however, VMPFC activation did not distinguish between strategies. Distinct medial prefrontal regions also encoded consistency with situational norms. A separate network, including right temporoparietal junction and parahippocampal gyrus, was more activated for inferential errors in the donation than in the savings condition. These results demonstrate that neural responses to others' generosity or selfishness depend not only on their actions but also on their perceived intentions.

Impairment of prosocial sentiments is associated with frontopolar and septal damage in frontotemporal dementia

Poets and philosophers have long acknowledged moral sentiments as key motivators of human social behavior. Prosocial sentiments, which include guilt, pity and embarrassment, enable us to care about others and to be concerned about our mistakes. Functional imaging studies have implicated frontopolar, ventromedial frontal and basal forebrain regions in the experience of prosocial sentiments. Patients with lesions of the frontopolar and ventromedial frontal areas were observed to behave inappropriately and less prosocially, which could be attributed to a generalized emotional blunting. Direct experimental evidence for brain regions distinctively associated with moral sentiment impairments is lacking, however. We investigated this issue in patients with the behavioral variant of frontotemporal dementia, a disorder in which early and selective impairments of social conduct are consistently observed. Using a novel moral sentiment task, we show that the degree of impairment of prosocial sentiments is associated with the degree of damage to frontopolar cortex and septal area, as assessed with 18-Fluoro-Deoxy-Glucose-Positron Emission Tomography, an established measure of neurodegenerative damage. This effect was dissociable from impairment of other-critical feelings (anger and disgust), which was in turn associated with dorsomedial prefrontal and amygdala dysfunction. Our findings suggest a critical role of the frontopolar cortex and septal region in enabling prosocial sentiments, a fundamental component of moral conscience.

Unravelling the mystery of pain, suffering, and relief with brain imaging

In humans, the experience of pain and suffering is conveyed specifically by language. Noninvasive neuroimaging techniques now provide an account of neural activity in the human brain when pain is experienced. Knowledge gleaned from neuroimaging experiments has shaped contemporaneous accounts of pain. Within the biopsychosocial framework, nociception is undoubtedly required for survival, but is neither necessary nor sufficient for the consciousness of pain in humans. Pain emerges from the brain, which also exerts a top-down influence on nociception. In the brains of patients with chronic pain, neuroimaging has revealed subtle but significant structural, functional, and neurochemical abnormalities. Converging evidence suggests that the chronic pain state may arise from dysfunction of the frontal-limbic system. Further research in the clinical pain population will continue to identify neural mechanisms that contribute to the experience and consequence of pain, which may then be targeted therapeutically.

On the neuro-cognitive foundations of basic auditory number processing: an fMRI study

Background

It is widely agreed that numbers automatically activate a magnitude representation. Nevertheless, so far no systematic evaluation of the neuro-cognitive correlates has been provided for the case of auditorily presented numbers.

Methods

To address this question, we presented spoken number words in three different tasks (passive listening, magnitude comparison, parity judgement) as well as spoken pseudowords in an fMRI study.

Results

We found IPS activation typically associated with magnitude processing in all tasks with numerical stimuli only. Interestingly, directly contrasting the two semantic tasks magnitude comparison (magnitude-relevant) and parity judgement (magnitude-irrelevant) revealed a left lateralized predominance within the IPS for the processing of parity information as compared to a right lateralization for number magnitude for auditorily presented number words.

Conclusions

In summary, our results suggest a highly automatic activation of number magnitude for spoken number words similar to previous observations for visually presented numbers, but also indicate that the issue of hemispheric asymmetries deserves specific consideration.

Responses to ostracism across adulthood

Ostracism is ubiquitous across the lifespan. From social exclusion on the playground, to romantic rejection, to workplace expulsion, to social disregard for the aged, ostracism threatens a fundamental human need to belong that reflexively elicits social pain and sadness. Older adults may be particularly vulnerable to ostracism because of loss of network members and meaningful societal roles. On the other hand, socioemotional selectivity theory suggests that older adults may be less impacted by ostracism because of an age-related positivity bias. We examined these hypotheses in two independent studies, and tested mechanisms that may account for age differences in the affective experience of ostracism. A study of 18- to 86-year-old participants in the Time-Sharing Experiments for the Social Sciences program showed an age-related decrease in the impact of ostracism on needs satisfaction and negative affectivity. A study of 53- to 71-year-old participants in the Chicago Health, Aging, and Social Relations Study (CHASRS) showed that ostracism diminished positive affectivity in younger (<60 years) but not older adults. Age group differences in response to ostracism were consistent with the positivity bias hypothesis, were partly explained by age differences in the impact of physical pain, but were not explained by autonomic nervous system activity, computer experience, or intimate social loss or stressful life experiences.

The neurobiology of moral behavior: review and neuropsychiatric implications

Morality may be innate to the human brain. This review examines the neurobiological evidence from research involving functional magnetic resonance imaging of normal subjects, developmental sociopathy, acquired sociopathy from brain lesions, and frontotemporal dementia. These studies indicate a "neuromoral" network for responding to moral dilemmas centered in the ventromedial prefrontal cortex and its connections, particularly on the right. The neurobiological evidence indicates the existence of automatic "prosocial" mechanisms for identification with others that are part of the moral brain. Patients with disorders involving this moral network have attenuated emotional reactions to the possibility of harming others and may perform sociopathic acts. The existence of this neuromoral system has major clinical implications for the management of patients with dysmoral behavior from brain disorders and for forensic neuropsychiatry.

Understanding others' regret: a FMRI study

Previous studies showed that the understanding of others' basic emotional experiences is based on a “resonant” mechanism, i.e., on the reactivation, in the observer's brain, of the cerebral areas associated with those experiences. The present study aimed to investigate whether the same neural mechanism is activated both when experiencing and attending complex, cognitively-generated, emotions. A gambling task and functional-Magnetic-Resonance-Imaging (fMRI) were used to test this hypothesis using regret, the negative cognitively-based emotion resulting from an unfavorable counterfactual comparison between the outcomes of chosen and discarded options. Do the same brain structures that mediate the experience of regret become active in the observation of situations eliciting regret in another individual? Here we show that observing the regretful outcomes of someone else's choices activates the same regions that are activated during a first-person experience of regret, i.e. the ventromedial prefrontal cortex, anterior cingulate cortex and hippocampus. These results extend the possible role of a mirror-like mechanism beyond basic emotions.

Social buffering of the stress response: diversity, mechanisms, and functions

Protracted or repeated activation of the hypothalamic-pituitary-adrenocortical (HPA) system is associated with a variety of physical and psychological pathologies. Studies dating back to the 1970s have documented many cases in which the presence of a social companion can moderate HPA responses to stressors. However, there also are many cases in which this "social buffering" of the HPA axis is not observed. An examination of the literature indicates that the nature of the relationship between individuals is crucial in determining whether or not social buffering of the HPA response will occur. Other factors that affect social buffering, either directly or by influencing the social relationship, include the social organization of the species, previous experience, gender, integration into a social unit, and the developmental stage at which individuals are examined. Current evidence suggests that social buffering involves mechanisms acting at more than one level of the CNS. It is suggested that, in addition to promoting health, social buffering may have evolved to direct the establishment of social relationships, and to facilitate developmental transitions in social interactions appropriate for different life stages.

Neural activity predicts attitude change in cognitive dissonance

When our actions conflict with our prior attitudes, we often change our attitudes to be more consistent with our actions. This phenomenon, known as cognitive dissonance, is considered to be one of the most influential theories in psychology. However, the neural basis of this phenomenon is unknown. Using a Solomon four-group design, we scanned participants with functional MRI while they argued that the uncomfortable scanner environment was nevertheless a pleasant experience. We found that cognitive dissonance engaged the dorsal anterior cingulate cortex and anterior insula; furthermore, we found that the activation of these regions tightly predicted participants' subsequent attitude change. These effects were not observed in a control group. Our findings elucidate the neural representation of cognitive dissonance, and support the role of the anterior cingulate cortex in detecting cognitive conflict and the neural prediction of attitude change.

The impact of social comparison on the neural substrates of reward processing: an event-related potential study

Event-related potentials (ERPs) were recorded to explore the electrophysiological correlates of reward processing in the social comparison context when subjects performed a simple number estimation task that entailed monetary rewards for correct answers. Three social comparison stimulus categories (three relative reward levels/self reward related to the other subject's) were mainly prepared: Self:Other=1:2 (Disadvantageous inequity condition); Self:Other=1:1 (Equity condition); and Self:Other=2:1 (Advantageous inequity condition). Results showed that: both Disadvantageous and Advantageous inequity elicited a more negative ERP deflection (N350-550) than did Equity between 350 and 550 ms, and the generators of N350-550 were localized near the parahippocampal gyrus and the medial frontal/anterior cingulate cortex, which might be related to monitor and control reward prediction error during reward processing. Then, Disadvantageous and Advantageous inequity both elicited a more late negative complex (LNC1 and LNC2) than did Equity between 550 and 750 ms. The generators of LNC1 and LNC2 were both localized near the caudate nucleus, which might be related to reward processing under social comparison.